Phase transitions and domain evolution in (Pb, La)(Zr, Sn, Ti)O_3 single crystal

摘要

Antiferroelectric (Pb, La)(Zr, Sn, Ti)O_3 (PLZST) single crystal has been grown and characterized. From dielectric measurements, x-ray diffraction analysis, and in situ observation of domain structures, we found two first-order phase transitions during heating from room temperature to 250 ℃: orthorhombic (O) → rhombohedral (R)→ cubic. Coexistence of O and R phases, with the R phase region strongly restricted inside the O phase matrix, has been observed within a broad temperature range above 123 ℃. In addition, much denser domain walls appeared in the PLZST crystal when the O-R transition takes place.